In railway vehicles, it is a known practice to install air handling systems, in particular air conditioning, including air handling units in each passenger compartment and a cooling machine for producing frigories, that is to say, negative heat energy which is capable of cooling an environment by extracting the heat from the interior of the vehicle, and discharging it into the exterior of the vehicle.
During the passage of vehicles through enclosed areas, such as tunnels, the discharging of heat into the exterior of the vehicle causes a heating of the air in the tunnels, which brings about a steady increase in the temperature in the tunnels.
In order to solve this problem, it is a known practice, in particular from the documents WO-2005/014365 and WO-2005/025959, to equip railway vehicles with storage units for storing frigories, for example in the form of ice or liquid maintained at a predetermined temperature in order to supply the cold source necessary for the air conditioning of the vehicle during its passing through a tunnel without operationally implementing the cooling machine and thus discharging the heat into the tunnel.
In the document WO-A-2005/014365, the frigories storage unit needs to be refilled regularly in particular with ice, while in the document WO-A-2005/025 959, the material that is used for storing frigories is ice produced during the time the vehicle is travelling in the open air with the help of a specific production unit by using in particular chemical products such as glycol.
Such technical solutions have the disadvantage of involving cumbersome frigories storage units that are not practical, and require regular refilling with specific products, that are used to produce the cold for cooling when passing through tunnels.